Ensure Location header on redirects before parsing

Fixes crash when HTTP redirect received without a Location header set.

Gemfile

@@ -1,3 +1,4 @@
 source 'https://rubygems.org'
 gem 'rest-client', '~>1.3'
-gem 'addressable', '~>2.3'
+gem 'addressable', '~>2.3'
+gem 'thin'

Gemfile.lock

@@ -2,13 +2,21 @@ GEM
   remote: https://rubygems.org/
   specs:
     addressable (2.3.4)
+    daemons (1.1.9)
+    eventmachine (1.0.3)
     mime-types (1.23)
+    rack (1.5.2)
     rest-client (1.6.7)
       mime-types (>= 1.16)
+    thin (1.5.1)
+      daemons (>= 1.0.9)
+      eventmachine (>= 0.12.6)
+      rack (>= 1.0.0)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
   addressable (~> 2.3)
   rest-client (~> 1.3)
+  thin

Rakefile

@@ -4,12 +4,22 @@ end
 task :build => 'server.js'
 
 namespace :test do
+  desc "Start test server"
+  task :server do |t|
+    $SERVER_PID = Process.spawn("ruby test/proxy_test_server.rb")
+  end
+
   desc "Run the tests against localhost"
   task :check do |t|
     system("ruby test/proxy_test.rb")
   end
+
+  desc "Kill test server"
+  task :kill_server do |t|
+    Process.kill(:QUIT, $SERVER_PID) && Process.wait
+  end
 end
-task :default => [:build, "test:check"]
+task :default => [:build, "test:server", "test:check", "test:kill_server"]
 
 Dir["tasks/*.rake"].each do |f|
   load f

server.coffee

@@ -98,6 +98,8 @@ process_url = (url, transferred_headers, resp, remaining_redirects) ->
           when 301, 302, 303, 307
             if remaining_redirects <= 0
               four_oh_four(resp, "Exceeded max depth")
+            else if !srcResp.headers['location']
+              four_oh_four(resp, "Redirect with no location")
             else
               is_finished = false
               newUrl = Url.parse srcResp.headers['location']

test/proxy_test.rb

@@ -4,6 +4,7 @@
 require 'openssl'
 require 'rest_client'
 require 'addressable/uri'
+require 'thin'
 
 require 'test/unit'
 
@@ -13,6 +14,14 @@ def config
       'host' => ENV['CAMO_HOST'] || "http://localhost:8081" }
   end
 
+  def test_proxy_survives_redirect_without_location
+    assert_raise RestClient::ResourceNotFound do
+      request('http://localhost:9292')
+    end
+    response = request('http://media.ebaumsworld.com/picture/Mincemeat/Pimp.jpg')
+    assert_equal(200, response.code)  
+  end 
+
   def test_proxy_valid_image_url
     response = request('http://media.ebaumsworld.com/picture/Mincemeat/Pimp.jpg')
     assert_equal(200, response.code)

test/proxy_test_server.rb

@@ -0,0 +1,11 @@
+require 'thin'
+
+class ProxyTestServer
+  def call(env)
+    [302, {"Content-Type" => "image/foo"}, "test"]
+  end
+end
+
+Thin::Server.start('127.0.0.1', 9292) do
+	run ProxyTestServer.new
+end